学习笔记 : Spring与MyBatis整合

传统DAO方式的开发整合

简介 : 采用传统DAO开发方式进行MyBatis与Spring框架的整合时,需要编写DAO接口以及接口的实现类,并且需要向DAO实现类中注入SqlSessionFactory,然后通过SqlSessionFactory创建SqlSession. 下面通过一个使用客户id查询数据表中客户信息的案例来演示该开发方式.

  1. customer.sql : 客户信息表

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    # 客户信息表
    create table t_customer (

    id INT(20) PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(10) NOT NULL,
    job VARCHAR(10) NOT NULL,
    phone VARCHAR(12) NOT NULL

    )
  2. db.properties : 数据库配置文件

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    #
    #database configuration information
    #
    jdbc.driver=com.mysql.cj.jdbc.Driver
    jdbc.url=jdbc:mysql:xxxxxx?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true
    jdbc.username=xxxxxx
    jdbc.password=xxxxxx
    #
    #DBCP configuration
    #
    jdbc.maxTotal=30 #最大连接数
    jdbc.maxIdle=10 #最大空闲连接数
    jdbc.initialSize=5 #初始化连接数
  3. applicationContext.xml : Spring核心配置文件

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    <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <!-- 读取db.properties -->
    <context:property-placeholder location="classpath:db.properties"/>
    <!-- 配置数据源 -->
    <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
    <!-- 数据库驱动 -->
    <property name="driverClassName" value="${jdbc.driver}"/>
    <!-- 连接数据库的url -->
    <property name="url" value="${jdbc.url}"/>
    <!-- 连接数据库的用户名 -->
    <property name="username" value="${jdbc.username}"/>
    <!-- 连接数据库的密码 -->
    <property name="password" value="${jdbc.password}"/>
    <!-- 最大连接数 -->
    <property name="maxTotal" value="${jdbc.maxTotal}"/>
    <!-- 最大空闲数 -->
    <property name="maxIdle" value="${jdbc.maxIdle}"/>
    <!-- 初始化连接数 -->
    <property name="initialSize" value="${jdbc.initialSize}"/>
    </bean>

    <!-- 事务管理器,依赖于数据源 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
    </bean>

    <!-- 开启事务注解 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

    <!-- 配置MyBatis工厂: 构建SqlSessionFactory -->
    <!-- 指定数据源和配置文件: 使得Spring IOC容器在初始化id为sqlSessionFactory的Bean时解析MyBatis的配置文件,并与数据源一同保存到Spring的Bean中 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!-- 注入数据源 -->
    <property name="dataSource" ref="dataSource"/>
    <!-- 指定核心配置文件位置 -->
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- 实例化Dao: 为SqlSessionDaoSupport类的子类对象注入一个SqlSessionFactory -->
    <bean id="customerDao" class="pers.huangyuhui.sm.dao.impl.CustomerDaoImpl">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

    </beans>
  4. mybatis-config.xml : MyBaits核心配置文件

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    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">

    <configuration>
    <!-- 配置别名 -->
    <typeAliases>
    <!-- 通过扫描包的形式定义别名: mybatis会将所有该包中的POJO类以首字母小写的非限定类名来作为它的别名 -->
    <package name="pers.huangyuhui.sm.po" />
    </typeAliases>

    <!-- 配置Mapper配置 -->
    <mappers>
    <mapper resource="pers/huangyuhui/sm/po/CustomerMapper.xml" />
    </mappers>
    </configuration>
  5. Customer.java : 持久层

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    package pers.huangyuhui.sm.po;

    /**
    * @ClassName: Customer
    * @Description: 客户信息
    * @author: HuangYuhui
    * @date: May 24, 2019 6:38:18 PM
    *
    */
    public class Customer {

    private Integer id;
    private String name;
    private String job;
    private String phone;

    public Integer getId() {
    return id;
    }

    public void setId(Integer id) {
    this.id = id;
    }

    public String getName() {
    return name;
    }

    public void setName(String name) {
    this.name = name;
    }

    public String getJob() {
    return job;
    }

    public void setJob(String job) {
    this.job = job;
    }

    public String getPhone() {
    return phone;
    }

    public void setPhone(String phone) {
    this.phone = phone;
    }

    @Override
    public String toString() {
    return "Customer [id=" + id + ", name=" + name + ", job=" + job + ", phone=" + phone + "]";
    }

    }
  6. CustomerMapper.xml : 映射文件

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    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

    <mapper namespace="pers.huangyuhui.sm.po.CustomerMapper">
    <!-- 根据id查询客户信息,其中`customer`为Customer类的别名 -->
    <select id="findCustomerById" parameterType="Integer" resultType="customer">
    select id,name,job,phone from t_customer where id = #{id}
    </select>
    </mapper>
  7. CustomerDao.java : DAO层

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    package pers.huangyuhui.sm.dao;

    import pers.huangyuhui.sm.po.Customer;

    /**
    * @ClassName: CustomerDao
    * @Description: TODO
    * @author: HuangYuhui
    * @date: May 24, 2019 6:52:30 PM
    *
    */
    public interface CustomerDao {

    /**
    * @Title: findCustomerById
    * @Description: 根据id查找客户信息
    * @param: id
    * @return: Customer
    */
    public Customer findCustomerById(Integer id);
    }
  8. CustomerDaoImpl.java : CustomerDao的实现类

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    package pers.huangyuhui.sm.dao.impl;

    import org.mybatis.spring.support.SqlSessionDaoSupport;

    import pers.huangyuhui.sm.dao.CustomerDao;
    import pers.huangyuhui.sm.po.Customer;

    /**
    * @ClassName: CustomerDaoImpl
    * @Description: 实现操作客户信息接口
    * @author: HuangYuhui
    * @date: May 24, 2019 6:54:24 PM
    */
    //注意:SqlSessionDaoSupport类在使用时需要一个SqlSessionFactory或一个SqlSessionTemplate对象,所以需要通过
    //Spring给SqlSessionDaoSupport类的子类对象注入一个SqlSessionFactory或SqlSessionTemplate.这样,在子类中就
    //能够调用SqlSessionDaoSupport类的getSqlSession()方法来获取SqlSession对象,并使用SqlSession对象中的方法!
    public class CustomerDaoImpl extends SqlSessionDaoSupport implements CustomerDao {

    private String mapperNamespace = "pers.huangyuhui.sm.po.CustomerMapper.";

    @Override
    // 通过id查找客户信息
    public Customer findCustomerById(Integer id) {
    // 调用SqlSessionDaoSupport类的getSqlSession()方法来获取SqlSession对象,并使用SqlSession对象中的方法!
    return this.getSqlSession().selectOne(mapperNamespace + "findCustomerById", id);
    }

    }

在此步骤需要在Spring配置文件applicationContext.xml中编写实例化CustomerDaoImpl的配置(已添加),代码如下所示 :

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<bean id="customerDao" class="pers.huangyuhui.sm.dao.impl.CustomerDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
  1. SMTest.java : 整合测试类

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    package pers.huangyuhui.sm.test;

    import org.junit.BeforeClass;
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;

    import pers.huangyuhui.sm.dao.CustomerDao;
    import pers.huangyuhui.sm.po.Customer;

    /**
    * @ClassName: SMTest
    * @Description: MyBatis+Spring整合测试
    * @author: HuangYuhui
    * @date: May 24, 2019 7:02:26 PM
    *
    */
    public class SMTest {

    private static ApplicationContext applicationContext;

    @BeforeClass
    public static void init() {
    applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    @Test
    public void findCustomerByIdTest() {
    // CustomerDao customerDao = (CustomerDao) applicationContext.getBean("customerDao");
    CustomerDao customerDao = (CustomerDao) applicationContext.getBean(CustomerDao.class);

    Customer customer = customerDao.findCustomerById(1);
    System.out.println(customer);
    }
    }
  2. log4j.properties : 日志文件

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    #Global configuration
    log4j.rootLogger=DEBUG,stdout
    #Log configuration
    log4j.logger.pers.huangyuhui.sm.test=TRACE
    #Console configuration
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.layout.ConversionPattern=%5p [%t] - %m%n
  3. 程序运行结果

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    Fetching JDBC Connection from DataSource
    JDBC Connection [1334618867, URL=xxxxxx, MySQL Connector/J] will not be managed by Spring

    ==> Preparing: select id,name,job,phone from t_customer where id = ?
    ==> Parameters: 1(Integer)
    <== Total: 1

    Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@15c25153]
    Returning JDBC Connection to DataSource
    Customer [id=1, name=YUbuntu0109, job=student, phone=15111111111]

Mapper接口方式的开发整合

. . .